Way back in February 2013, when Sony first announced the PlayStation 4, they talked a bit about their partnership with the streaming company Gaikai. With the power of the cloud, Sony said, we'd all be able to stream PS1, PS2, and PS3 games.
But things have changed. Today, those vague plans have coalesced into the form of PlayStation Now, a streaming service that lets you play... PS3 games. And only PS3 games.